我国典型湿热地区变质烟用香精中腐败微生物的多样性分析

Diversity of spoilage microorganisms in tobacco flavor in the typical hot-humid areas in China

摘要:

【背景】烟用香精是卷烟生产中的重要辅料，有些香精，特别是剩余的加料香精在运输和储存等过程中可能污染微生物，引起腐败变质发生。【目的】分析变质烟用香精中腐败微生物的群落多样性，确定引起加料香精变质的主要腐败微生物。【方法】采用稀释平板法，对我国典型湿热地区云南、福建和广西三地变质加料香精样品中的污染细菌、霉菌或酵母进行分离，分析其16S rRNA、ITS或26S rRNA基因序列，并通过反证试验确定引起变质的主要腐败微生物。【结果】所考察3个典型湿热地区变质加料香精存在不同程度的细菌、霉菌或酵母污染，其中细菌污染最为普遍。分离的76株污染细菌分布在2门4纲5目10科15属，细菌的群落多样性比较丰富，其中雷尔氏菌属(Ralstonia)、柠檬酸杆菌属(Citrobacter)、肠杆菌属(Enterobacter)及芽孢杆菌属(Bacillus)是优势菌群；9株霉菌分布在子囊菌门(Ascomycota)的3纲6属，每个属分离到1?2株霉菌；42株酵母分布在子囊菌门的6个属，其中毕赤酵母属(Pichia)、细枝钩酵母菌属(Wickerhamomyces)及酵母菌属(Saccharomyces)是优势菌群。云南和福建两地样品的细菌菌群组成明显多于广西，广西样品的霉菌菌群组成以及福建样品的酵母菌群组成均分别多于其余两地。反证试验结果显示，柠檬酸杆菌属、肠杆菌属、芽孢杆菌属、雷尔氏菌属和毕赤酵母属是引起烟用加料香精变质的主要腐败微生物。【结论】变质加料香精中污染微生物菌群组成及腐败微生物确定的研究将有助于我国湿热地区香精香料中污染微生物的控制和腐败变质的预防。

Abstract:

[Background] Tobacco flavor is an important auxiliary material in cigarette production. Microbial contamination usually occurs in the processes of transportation and storage of tobacco flavor, especially the residual casing, which could cause spoilage of tobacco flavor. [Objective] To investigate the diversity of spoilage microorganisms in the deteriorated tobacco flavor and identify the main spoilage microorganisms causing the deterioration of tobacco flavor. [Methods] Dilution plate counting method was applied to monitor the microbial composition of the deteriorated tobacco flavor from Yunnan, Fujian and Guangxi of typical hot-humid areas in China, and then the 16S rRNA, ITS or 26S rRNA genes of the isolates were sequenced. Furthermore, verifiable experiments were used to identify the main spoilage microorganisms causing deterioration of the tobacco flavor. [Results] The tobacco flavor samples from the three typical hot-humid areas in China were with different degree of bacteria, molds or yeasts contamination, and the bacterial contamination was the most common. A total of 76 bacterial strains, 9 fungal strains and 42 yeast strains were isolated. The 76 bacterial strains were distributed in 2 phyla, 4 classes, 5 orders, 10 families and 15 genera. Ralstonia, Citrobacter, Enterobacter and Bacillus were the dominant genera. The 9 fungal strains were distributed in 3 classes and 6 genera of the Ascomycota phyla, with 1?2 fungal strains belonging to each genus. The 42 yeast strains were distributed in 6 genera of Ascomycota. Pichia, Wickerhamomyces and Saccharomyces were the dominant genera. The bacterial composition of Yunnan and Fujian samples was obviously more than that in Guangxi. The fungal composition of Guangxi and yeasts’ composition of Fujian were more than those in the other two sites, respectively. The verifiable experiment results showed Citrobacter, Enterobacter, Bacillus, Ralstonia and Pichia were the main spoilage microorganisms in the tobacco flavor samples. [Conclusion] The study on the composition of contaminated microorganisms and the confirmation of spoilage microorganisms in the deteriorated tobacco flavors could help to control the contamination of microorganisms and the spoilage of tobacco flavors in hot-humid areas in China.